/* ========================================================================
 * PlantUML : a free UML diagram generator
 * ========================================================================
 *
 * (C) Copyright 2009-2024, Arnaud Roques
 *
 * Project Info:  https://plantuml.com
 *
 * If you like this project or if you find it useful, you can support us at:
 *
 * https://plantuml.com/patreon (only 1$ per month!)
 * https://plantuml.com/paypal
 *
 * This file is part of PlantUML.
 *
 * PlantUML is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * PlantUML distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
 * License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 *
 * Original Author:  Arnaud Roques
 *
 *
 */
package io.kroki.server.decode.transcoder;

import java.io.IOException;

import static java.nio.charset.StandardCharsets.UTF_8;

public class TranscoderImpl implements Transcoder {

  private final Compression compression;
  private final URLEncoder urlEncoder;
  private final StringCompressor stringCompressor;
  private final Format format;
  private TranscoderImpl(URLEncoder urlEncoder, StringCompressor stringCompressor, Compression compression,
                         Format format) {
    this.compression = compression;
    this.urlEncoder = urlEncoder;
    this.stringCompressor = stringCompressor;
    this.format = format;
  }

  public static Transcoder utf8(URLEncoder urlEncoder, StringCompressor stringCompressor, Compression compression) {
    return new TranscoderImpl(urlEncoder, stringCompressor, compression, Format.UTF8);
  }

  // ::comment when __CORE__
  public static Transcoder upf9(URLEncoder urlEncoder, StringCompressor stringCompressor, Compression compression) {
    return new TranscoderImpl(urlEncoder, stringCompressor, compression, Format.UPF9);
  }

  public String encode(String text) throws IOException {
    final String stringAnnoted = stringCompressor.compress(text);
    final byte[] data;
    // ::comment when __CORE__
    if (format == Format.UPF9)
      data = Upf9Encoder.getBytes(stringAnnoted);
    else
      // ::done
      data = stringAnnoted.getBytes(UTF_8);

    final byte[] compressedData = compression.compress(data);

    return urlEncoder.encode(compressedData);
  }
  // ::done

  public String decode(String code) throws NoPlantumlCompressionException {
    try {
      final byte[] compressedData = urlEncoder.decode(code);
      final ByteArray data = compression.decompress(compressedData);
      final String string;
      // ::comment when __CORE__
      if (format == Format.UPF9)
        string = data.toUPF9String();
      else
        // ::done
        string = data.toUFT8String();
      return stringCompressor.decompress(string);
    } catch (Exception e) {
      // System.err.println("Cannot decode string");
      throw new NoPlantumlCompressionException(e);
    }
  }

  enum Format {
    UTF8, UPF9
  }

}
